If you are having trouble with a multi-step login, there is a good chance it is because the data was imported from the ff/ie pw mgr (or some other password manager) and there was not enough information for LastPass to know that it is a multi-step login.

I would suggest in that case to delete your site in LastPass and use LastPass to add the site (i.e., go to the site and login as usual and let LastPass capture it).

That will give you the best chance of it working. If it still doesn't work, let us know and we will have to look at it.